I am the inheritor of some old radios that have been passed down in the family, going back to a radio which must have been purchased by my grandfather around 1927. That RCA Radiola 17 radio is described here. I recently got this radio working again, likely for the first time since about 1935. This paper describes the journey, both the repairs made and some analysis of how it now performs. This radio was the first of RCA's plug-in radios; earlier radios had to work off of batteries. It took quite a few batteries, something like 10, to power the earlier and quite similar Radiola-16. Radio technology was developing rapidly.
Below is a presentation given at Wilkes university on March 21, 2023 on early radios. This includes some material on early radios of the 1900 to 1940 era, then developments afterward. The progress is illustrated by three radios from my family history. The Radiola 17, dating to 1927, is the earliest. It is not superheterodyne, as most radios are after 1930 or so. This radio was replaced by a large console model in the around 1930 or later, which seems to have disappeared except for the cabinet. The Hallicrafters D-20 radio, dating to 1939, was purchased by my father on Guam during World War 2, likely in 1945. I recall using it myself about 1963 and after. It has lots of big improvements, such as AGC, Superheterodyne, BFO, and four different bands. Unlike the Radiola 17, it could be aligned to give good performance. The third radio, a common Emerson All American Five (AA5) type, reduces the complexity and cost to allow mass production at a low price. This particular radio from 1949 was in our dining room. We would listent to radio shows such as The Shadow and Johnny Dollar, as well as news and editorial - Fulton Lewis Jr. That's as much as I recall. You won't hear those now! Of course, Radio developed much further later, but this short 1927 to 1949 era showed an amazingly rapid transition of technology that is interesting.
Early Radio presentation of March 21, 2023